The Cooling & Heating Specialists

Living and working in a comfortable environment

1. What is air conditioning?

The purpose of air conditioning is to control the filtration, air movement, temperature and humidity of an atmospheric environment. Air conditioning is always associated with the cooling and dehumidification process of air and is always therefore identified with refrigeration equipment.

The full control over relative humidity by the addition of moisture by means of a humidifier and the use of a humidifier constitutes full air conditioning, but this control is not always exercised. However, the more often used partial or comfort air conditioning which uses refrigeration equipment only and is therefore capable of cooling as well as dehumidifying is still referred to as air conditioning.

From the foregoing therefore the term 'ventilation' should not be confused with air conditioning as refrigeration equipment is not necessarily provided with ventilation equipment.

2. What is relative humidity?

The atmosphere always contains moisture in the form of water vapor. The maximum amount of water vapor that may be contained in the air depends on the temperature of the air and the higher the temperature of the air, the more water vapor may be contained. At high temperatures and high moisture contents extreme discomfort is experienced as the evaporation of moisture from the body into the atmosphere by the process of perspiration becomes difficult.

In the air conditioning process the moisture content of the air may be reduced by the use of a cooling coil or added by the use of a humidifier.

The term relative humidity is simply a ratio between the actual moisture content of the air compared with the moisture content of the air required for saturation at the same temperature, ie at 100% relative humidity (also known as saturation point).

The air conditioning engineer uses the psychometric chart to analyze how the state of moist air alters as an air conditioning process takes place.